1. Field of the Invention
The present invention relates to a mobile communication system and, more particularly, to a video call receiving service using a sub-address of the mobile communication system.
2. Background of the Related Art
Generally, a mobile communication system is a communication system featuring radio communication between a moving element, such as a ship, airplane, and car, and a fixed station. Types of mobile communication include land mobile radio communication, oversea mobile radio communication, and air mobile radio communication, according to the locations where the moving radio station moves. The mobile communication system may employ an Advanced Mobile Phone Service (AMPS) system protocol using an analog method, a Code Division Multiple Access protocol (CDMA), a Time Division Multiple Access (TDMA) system protocol, a Frequency Division Multiple Access (FDMA) system protocol using a digital method, a Personal Communication System (PCS) protocol, and an International Mobile Telecommunication in the year 2000 (IMT-2000) system protocol.
FIG. 1 illustrates a background art mobile communication system structure. The mobile communication system comprises a terminal 10 that supports the AMPS system and the CDMA system, selectively or simultaneously, and allows a subscriber to communicate through the mobile communication network. A base station 20 performs the communication with the terminal 10 using an IS-95 protocol in a radio section. A control station 30 connected to the base station 20 controls a radio link and a wired link and also performs a hand-off function. An exchanger 40 connected to the control station 30 constructs a communication path of the subscriber and connects to another communication network.
Therefore, the terminal is able to perform a call through the base station 20, the control station 30, and the exchanger 40. A numbering system of the CDMA mobile terminal is designed to make a call by allocating one number for one terminal 10. However, the mobile terminal does not differentiate a video call and a voice call. Therefore, only one number is allocated to a video terminal without division between the video call and the voice call.
The IS-95 CDMA mobile terminal uses one of two numbering systems, such as an American Standard Code for Information Interchange (ASCII) system and a Dual Tone Multi-Frequency (DTMF) system. Presently, the CDMA terminal in Korea uses the DTMF system. However, the CDMA terminal transmits the telephone number using a message in a radio section, not using call processing in a band like in a wired telephone. Also, the CDMA method allocates only one telephone number to a Mobile Identification Number (MIN) applied to a terminal.
If a video terminal method based on an ITU-T H.324 standard is applied to the mobile terminal, the subscriber cannot select to answer the call as a video call or a voice call, because the video terminal method is operated by recognizing a general physical layer as a device, such as a modem.
Therefore, the subscriber may pre-designate a setting for receiving either the voice call or the video call, in order to answer the call as the video call or the voice call. However, even in this case, the mobile terminal can only be used for the pre-designated use.
That is, according to the method for video call receiving in a mobile communication system of the background art, there is no certain method for distinguishing the video call and the voice call. This is because a standard for receiving the video call of the CDMA video terminal is not designated, and the method in which call kinds of the mobile terminal are pre-designated, for solving the above problem, is able to receive only the pre-designated kinds of calls.